Salivary Function is known to be affected adversely by radiation treatment and chronically by Sjogren's Syndrome. Patients undergoing radiation therapy will be studied with Nuclear Medicine Salivary Studies and the affect of drugs to ameliorate the changes will be assessed as well as with other clinical measurement including salivary analysis. Patients will be having studies prior to radiation therapy and follow-up scans to allow comparison. The magnitude of changes will be assessed by time activity curves and responses to washout with citric acid stimulation. Patients with Sjogren's Syndrome also will have drug treatment to attempt an enhancement of salivary function. This also be assessed by salivary analysis and Nuclear Medicine studies with time activity curves and washouts after citric acid stimulation.